Image analysis apparatus, method, and program

Patent metadata

Field	Value
Publication number	US-9117287-B2
Application number	US-201414489529-A
Country	US
Kind code	B2
Filing date	Sep 18, 2014
Priority date	Mar 23, 2012
Publication date	Aug 25, 2015
Grant date	Aug 25, 2015

Abstract

An image analysis apparatus that analyzes, based on a series of three-dimensional images of lungs at different time phases, a three-dimensional distribution of ventilation volume of the lungs, includes a lung region extraction unit that extracts a lung region from each of the three-dimensional images; an alignment unit that aligns the lung regions between the series of three-dimensional images and calculates a displacement vector field in the lung region; a function calculation unit that calculates a local ventilation volume function representing a temporal change in ventilation volume at each point in the displacement vector field in each of the three-dimensional images based on the displacement vector field; and a quantification unit that quantifies a difference between the local ventilation volume function and a benchmark ventilation volume function serving as a reference and calculates a quantitative value representing the difference.

First claim

What is claimed is:

1. An image analysis apparatus that analyzes, based on a series of three-dimensional images of lungs at different time phases, a three-dimensional distribution of ventilation volume of the lungs, the apparatus comprising:
a lung region extraction unit that extracts a lung region from each of the three-dimensional images;
an alignment unit that aligns the lung regions between the series of three-dimensional images and calculates a displacement vector field in the lung region;
a function calculation unit that calculates a local ventilation volume function representing a temporal change in ventilation volume at each point in the displacement vector field in each of the three-dimensional images based on the displacement vector field; and
a quantification unit that quantifies a difference between the local ventilation volume function and a benchmark ventilation volume function serving as a reference and calculates a quantitative value representing the difference.

2. The image analysis apparatus as claimed in claim 1 , wherein the quantification unit calculates a difference function representing a difference between the local ventilation volume function and the benchmark ventilation volume function as the quantitative value.

3. The image analysis apparatus as claimed in claim 1 , wherein the quantification unit calculates a difference function representing a difference between the local ventilation volume function and the benchmark ventilation volume function, and calculates an integration value of absolute values of ventilation volumes or a maximum value of the absolute values of the difference function as the quantitative value.

4. The image analysis apparatus as claimed in claim 1 , wherein the quantification unit calculates a difference in time to reach a predetermined ventilation volume between the local ventilation volume function and the benchmark ventilation volume function as the quantitative value.

5. The image analysis apparatus as claimed in claim 1 , wherein the apparatus further comprises a display control unit that visualizes the quantitative value on the three-dimensional images displayed or on two-dimensional images obtained from the three-dimensional images.

6. The image analysis apparatus as claimed in claim 5 , wherein the display control unit visualizes the quantitative value by mapping the quantitative value on each point in the displacement vector field in each of the three-dimensional images or each of the two-dimensional images.

7. The image analysis apparatus as claimed in claim 1 , wherein the alignment unit performs the alignment by a non-rigid registration method.

8. The image analysis apparatus as claimed in claim 1 , wherein the alignment unit performs the alignment based on a correlation between the three-dimensional images.

9. The image analysis apparatus as claimed in claim 1 , wherein the three-dimensional images are generated from CT images or MRI images.

10. The image analysis apparatus as claimed in claim 1 , wherein the quantification unit quantifies the difference after normalizing the local ventilation volume function and the benchmark ventilation volume function in a time axis direction.

11. The image analysis apparatus as claimed in claim 1 , wherein the quantification unit quantifies the difference after normalizing the local ventilation volume function and the benchmark ventilation volume function by a maximum value of the local ventilation volume function or the benchmark ventilation volume function.

12. The image analysis apparatus as claimed in claim 1 , wherein the benchmark ventilation volume function is a function representing a volume change in the entire lungs of the same subject as that for which the three-dimensional images are obtained, a vital capacity function of the same subject, a function representing a volume change in a partial region of the lungs of the same subject, a ventilation volume function calculated based on many healthy persons, or a ventilation volume function calculated mathematically.

13. An image analysis method that analyzes, based on a series of three-dimensional images of lungs at different time phases, a three-dimensional distribution of ventilation volume of the lungs, the method comprising:
extracting a lung region from each of the three-dimensional images;
aligning the lung regions between the series of three-dimensional images and calculating a displacement vector field in the lung region;
calculating a local ventilation volume function representing a temporal change in ventilation volume at each point in the displacement vector field in each of the three-dimensional images based on the displacement vector field; and
quantifying a difference between the local ventilation volume function and a benchmark ventilation volume function serving as a reference and calculating a quantitative value representing the difference.

14. A non-transitory recording medium on which is recorded a program for causing a computer to perform an image analysis method that analyzes, based on a series of three-dimensional images of lungs at different time phases, a three-dimensional distribution of ventilation volume of the lungs, the program causing the computer to perform the steps of:
extracting a lung region from each of the three-dimensional images;
aligning the lung regions between the series of three-dimensional images and calculating a displacement vector field in the lung region;
calculating a local ventilation volume function representing a temporal change in ventilation volume at each point in the displacement vector field in each of the three-dimensional images based on the displacement vector field; and
quantifying a difference between the local ventilation volume function and a benchmark ventilation volume function serving as a reference and calculating a quantitative value representing the difference.

Assignees

• Fujifilm Corp

Inventors

• Masumoto Jun

Classifications

• G16H50/30

  for calculating health indices; for individual health risk assessment · CPC title

• A61B6/5217

  extracting a diagnostic or physiological parameter from medical diagnostic data · CPC title

• G06T7/33

  using feature-based methods · CPC title

• G06T2207/10088

  Magnetic resonance imaging [MRI] · CPC title

• G06T2207/30061

  Lung · CPC title